How is varicella transmitted and for how long is an infected person contagious?

The varicella zoster virus (VZV) spreads from person to person by direct contact or through the air by coughing or sneezing. It is highly contagious. It can also be spread through direct contact with fluid from a blister of a person infected with varicella, or from direct contact with a skin lesion from a person with zoster (shingles). People with varicella are infectious 1 to 2 days before skin lesions appear until all lesions have crusted over, usually 4 to 7 days after the appearance of skin lesions.